432 MHz 10 Element Yagi
Antenna
This is a 2 wavelengths antenna for 432 MHz. Here is a
simulation and an optimization of this antenna made by
Winkler Antennen. I used this antenna for a while.
(20 Nov 2007)

DF9CY Full-Size
Vertical for 7,05 MHz
In 2006 I had this full-size vertical up for a while. Now I
simulated the antenna with some astonishing results when
comparing it to the dipole antenna.
(20 Nov 2007)

DF9CY 6 Element 50
MHz (Long Version)
This article describes a six element antenna for the 50 MHz
band, which has a significantly improved performance over my
old design (see below). I used it a while ago with good
success.
(01 Oct 2007)

The DF9CY SIX ELEMENT Antenna for
50 MHz
This article describes my 6 element antenna for the 50 MHz
Amateur Radio Band, which has some significant improvements
over the 4 element antenna. Included are the dimensions, some
results, diagrams and the downloadable EZNEC file.

The "Leonid Magic"
for 50 MHz
Short time before the Leonid meteor shower of 1998 (the big
one) I had the idea of pointing an antenna with a broad main
lobe straight up into the sky. I it was really a big success.
Here is an image of this antenna.

"Magic
Fifty"
My 50 MHz transverter (144 MHz input) which I developped in
1990. It is completely in SMD technology. A reprint of the
DUBUS Articles from 3/1991 (part 1). German & English and
The Addendum 1/1993 (part 2).

Microwave

24 GHz
Transverter
Some information about my 24 GHz transverter can be found here.
(11 April 2008)

Showcase and Reviews

Sommerkamp FT250
A Nostalgia Sommerkamp FT-250 came "along the way" ... Here are
some images of this radio, which is fully working.
(25 January 2008)

TenTec RX320D
Modifications and an overview and a lab-test of my PC-only
controlled 100 kHz to 30 MHz receiver. (09 June 2004)

KENWOOD TS690S
A lab-test on my all-mode transceiver for shortwave and 50 MHz
(An article I wrote in 1991 for "Funktelegramm" - in German and
English).
Added a HOW-TO expand the TS690 for 30 kHZ to 60 MHz
coverage.

Other

LINRAD
Installation
Installation of Linrad - a software radio - under SuSE Linux
9.1. Works on Knoppix 3.7 too. (16 May 2005)